Surveying apparatus



April 1 940.

F. E. PATT ON SURVEYING APPARATUS Filed Nov. 6, 193'? Patented Apr. 30, 1940 UNITED STATES PATENT OFFICE SURVEYING APPARATUS Application. November 6, 1937, Serial No. 173,161

7 Claims.

This invention relates to apparatus for determining straightness of a pipe, bar, column, or other long object having a vertical axis of symmetry, and is more particularly related to an 5 apparatus for determining the straightness of a 'sists of a multiplicity of pipe sections secured together by connecting collars known as tool joints. The drill string is rotatably supported or suspended from a derrick positioned at the top of the well hole. The uppermost section known 20 as the kelly is usually of polygonal cross-section tojafford a driving connection with a machine for rotating the drill stem.

The drill string carries-at its lower end a drilling bit and the drill string is formed of pipe 25 sections so that drilling fluid may be pumped through the drill string and out holes formed in the drilling bit in order that the drilling bit in its operation may operate under the influence of the drilling mud.

30 In operation this drill string is subject to very severe service and failure and breakage is not uncommon. The weight of such drill string during operation may exceed one hundred tons as suspended within the derrick and the length of 35 such drill string may, and often does, exceed flve to ten thousand feet in length. Failure of such drill stems or in the tool joints which connect the sections results in, expansive fishing operations, or.may even result in theloss of 40 the 11016.

It has been found that one of the principal causes of failure of such a drill string is a bent section in the drill stem. Upon rotation this bent section turns eccentrically and sets up 45 stresses that soon cause failure and breakage. A bent drill collar, as well as a bent section, is liable to, and often does, result in such failure.

In testing such drill strings, collars, etc., it is advantageous to be able to test the straightness of such-sections of pipe and collars as theyare being lowered into the well or connected in the drill string in order that a determination may bemade of their true condition at the time of their use. An apparatus which is to be utilized 55 in determining the straightness of such drill stem at the time of use must be capable of use during the operation of making up the drill stem without materially interfering with the operation .of adding sections to the drill stem.

It is therefore an object of this invention to provide an apparatus which may be used for the determining of straightness of each section of drill string at the time it is being raised to position to be added to the drill string prior to its being lowered into the bore hole.

Another object of the present invention is to provide an apparatus for determing the straightness of sections of a drill string, which apparatus includes a target member which is adapted to be mounted upon the drill string section near its upper end as such section is being raised into its position of suspension, and a means which is adapted to be applied to the drill string near its lower end from a position near the floor of the'well derrick and which is operable in connection with such target means by mere application to the drill string in order to determine the condition of straightness of said drill string section. Another object of this invention is to provide an apparatus for determining the straightness of a section of drill string prior to its being added to the drill string and which apparatus includes a target means which is adapted to be applied to the upper end of the drill string as it is being lifted into position of suspension within the well derrick and which target means includes a plurality of angular related target arms carrying target indicators which are utilizable in connection with an observing apparatus adapted to be applied to the pipe near 'the floor of the derrick so that the condition of straightness of the pipe maybe determined in several planes.

Another object of this invention is to provide an apparatus for determining the straightness of a pipe, which apparatus is susceptible to use 40 on pipes or bars having square or circular crosssection without requiring adjustments to be made in the device as applied to such bars or pipe for the purpose of permitting such determinations of straightness to be made.

Another object of this invention resides in the provision of an apparatus for determining the straightness of a section of pipe or the like, which apparatus includes a target member which is associated with a light source and a fighting instrument whereby the target reading is made visible, to an observer by a reflected light. Other objects and advantages of this invenit is believed will be apparent from the following detailed description of a preferred embodiment thereof as illustrated in the accompanying drawing.

In the drawing:

Flgure 1 is a general perspective view of a section of drill string as suspended within a well derrick and illustrating a surveying apparatus embodying this invention as applied to, and used in, checking the straightness of such section or stand of drill pipe.

Figure 2 is a sectional elevation of a preferred form of sighting apparatus embodying my invention illustrating the same as adapted to a broken section or stand of drill pipe.

Figure 3 is an end view of the apparatus as illustrated in Figure 2.

Figure 4 is an end elevation of a target embodied in my invention illustrating the same as adapted or applied to a section of drill pipe and illustrating the same in horizontal section.

Figure 5 is a plan view of a modified form of target embodied in my invention.

Figure 6 is a side elevation of a modified form of target illustrated in Figure 5.

Figure 7 is a plan view of a portion of the target illustrating the same as viewed through the sighting apparatus embodied in my invention.

In the drawing I indicates a stand or section of a drill string illustrated as suspended by means of a well elevator 2 from a hook 3. This stand or section of drill string is illustrated in position within a well derrick (not shown) as the same would be positioned preparatory to adding the same to the drill string which extends into. a well hole.

The section or stand of drill string I is usually raised in the derrick from a horizontal position preparatory to adding the same to the drill string. As the drill pipe is raised to its suspended position, a target 4, or a plurality of angularly arranged targets 4, are applied to the pipe so that the target arms extend outwardly from the axis of the pipe and are angularly arranged one relative to the other. If the stand I of the drill stem is standing within the well derrick, the targets 4 may be applied to the up per end by the derrick man.

The observer 5 standing upon the derrick floor then applies the sighting device 6 to the pipe in position so that the telescope I thereof lies substantlally parallel with the axis of the section I. The sighting device may be equipped with an illuminating means II. The telescope I is formed with a right-angle eye-piece 9. The observer 5 holds the sighting device 6 in position on the section I to view one of the targets 4 through the telescope I. Each of the targets 4 includes a plurality of outwardly spaced indicators I0 which are illuminated by the lighting device 8. By observing which of these indicators lies upon' the reference-line II of the telescope, the operator is enabled to determine whether or not the section I is straight or bent in the particular plane in which the observation is being made. By moving the sighting device 8 around to ascend position upon the section I until the second target 4 is viewed in the same manner, the operator is enabled to determine quickly the condition of straightness of the section I without materially delaying the operation of adding the section I to the drill string. If the pipe section I is straight and is then connected with the drill string, the targets 4 may be removed from the upper end of the drill string by the observer 5 as the stand or section I is lowered into the well hole to a position where the targets 4 may be reached by the observer 5.

' justment I4 The telescope I is mounted upon the frame of the sighting device 6 in position so that the longitudinal axis of the telescope I will align with, or be parallel with, the principal axis of the pipe I. In order to so position the telescope I with reference to the pipe I, the sighting device is provided with a pair of longitudinally spaced brackets I2, each of which is formed with a 90 V-notch I3. The V-notches I3 of the brackets I2 are so formed that upon mere holding of the sighting device Ii firmly against the stand I or the drill collar, the longitudinal axis of the telescope I is positioned parallel and in alignment with the axis of .the stand I.

The telescope is formed with a focusing adwhich may be of any suitable or desirable construction as is well understood in the art.

The lighting device 8 'as carried by the sighting device 6 may be of any suitable or desirable construction and is herein illustratedas including a flashlight of ordinary construction operated by batteries and including a switch I5 which, in

the embodiment shown, is mounted upon the frame of the sighting device 6. The cross-hair or reference line II is carried within the telescope I in a manner well understood in the art and as this invention is not particularly directed to the construction of such telescope I, it is believed that it would serve no useful purpose particularly to describe or set forth in detail the construction of this well known instrumentalitv.

The targets 4 are preferably formed with two angularly extending legs I6 formed to provide a- V-notch I'I between them similar to the V- notch I3. The targets are releasably held in position by means of a clamping means consisting of a strap I! provided at its free ends with an adjustment clasp I9 and held intermediate its ends within the body of the target 4 by means of a spring 20 secured in position as indicated at II. The spring 20 acts to hold the strap I8 under tension to thereby maintain the tar et 4 flrmly in position against the periphery of the pipe stand I. Each of the targets 4 includes the outwardly extending target arm 22 along which the indicators I0 are spaced. The indicators II as illustrated include a plurality of reflectors which may be formed of difierent colored glass. The central reflecting indicator 23 may be, for example, a white glass with two adjacent reflectors lying immediately on each side of the reflectors 23 formed of red glass and the two outer reflectors may be formed of another colored glass, such for example, as green glass. The central reflector 23 is positioned at the same distance from the axis of the pipe upon the axis of the telescope I. Thus as indicated in Figure 7, when the central or white reflctor indicator 23 lies'upon the hair-line II, the indication is that the stand I is, in the particular plane of the test, straight. flmould the hairline II lie away from the center of the reflector 23, either toward the red, green or other colored reflectors II, the indication is that the pipe is bent in the particular plane in which the test is being determined.

A measure of the deviation from the theoretical straightness of the pipe I is given by the number of reflectors II between the cross-hair. II and the white reflector 2i and the direction of the bend either concave or convex is indicated by the position of the white reflector as to the hairor reference line II. -Thus if the white light 23 is on the side of the reference line toward themetlasis' the pipe, the indication is of a concave bend. Conversely, if the white light is upon the opposite side of the reference line H, the indication is of a convex bend in the pipe. -By taking two or more determinations at different angles by the' use of the multiple target 4, an indication of the exact condition and direction of bend in, the

stand I may be had. It will be noted by referenceto the drawing that when the sighting instrument 6 and targets [are positioned at opposite endsof the member .I the determination arrived at is in eflect a measure of the co-axial alignment of the ends of the member I.

strap 21 may be formed as a spring or of elastic material in order to hold the target in position upon the pipe I.

The plate 25 is formed with a plurality of concentrically positioned semi-circular indicating lines 30.v The advantage of this type of target is that instead of employing a multiple target including two target arms as illustrated in connection with the targets 4, only a single target is required and the worker may determine the positionof the straightness or bend of the pipe I by positioning the sighting device at a multiplicity of positions around the pipe I and making the tests with reference to the concentric circle 3| positioned in a manner'similar toithat of the white indicating reference reflector 23. The reference indicating semi-circle 3| has a radius equal to the distance of the axis of th telescope 1 from the axis of the pipe I.

The color system described in connection with the reflectors ill may be utilized in connection with the reference lines 30 or reference numerals may be placed upon the concentric circles so that they may be observed in the telescope 1.

Having fullydescrlbed my invention, it is to be understood that I do not wish to be limited to the details herein set forth, but my invention is of the full scope of the appended claims.

I claim: v

1. In a device of the class described for testing the straightness of a vertical member, the' combination of, a sighting instrument having a principal optical axis, aligning means on -said sighting instrument adapted to contact the exterior surface of the member in a plurality of angular positions, said aligning means acting to hold said optical axis and the axis of that portion of the member adjacent the instrument in substantially parallel relation for all such positions, a target on said member at a location vertically spaced from said instrument, scale means associated with said target including an arc of a circle, the radius .of the circle being equal to the distance between, said axes at the location of the sighting instrument.

2. In a device of the class described for testing the straightness of a vertical member, the combination of, 'a sighting instrumenthaving its principal axis oriented in a direction substantially vertical, means including a pair of vertically spaced elements secured to said sighting instrument and adapted to contact the exterior surface of the member in a plurality of angular positions, said elements acting to hold the principal axis of the sighting instrument and the of said target arms.

axis of that portion of the member intermediate .the elements in parallel relation, a target on said member at a location vertically spaced from said instrument, scale means on said target including a portion of a series oi. concentric circles, whereby the convergence or divergence of said axes at said target location may be observed at a plurality of positions on said scale means.

3. In a device of the class described for testing the straightness 01' a vertical member, a

' target, having in combination, a pair of legs form'- ing a v-notch, a projecting body portion secured to said legs in symmetrical relation, said V-notch being adapted to contact the exterior sm'face of said vertical member so that the longitudinal axis thereof adjacent the target is at right angles to said projecting body portion, a straightnessindicating scale 'on said body portion, means to detachably secure the target upon the vertical member, said means including a flexible element associated with the legs of said V-notch and adapted to encircle said vertical member, and resilient means mounted within the body portion ber to hold said flexible element undertension.

4. In a .device for measuring the straightness of a vertical suspended pipe, the combination of a target secured to the pipe near its upper end, said target including a plurality of angularly related target arms each of which is provided with indicators, and a sighting device adapted to be applied to the pipe in position parallel to the and adantedto act radially of said vertical memaxis of the pipe and along its length below said target, and adapted to be shifted around said pipe to optically position the same in vertical alignment with saidtarget arms. I

5. In a device of the class described for determining the co-a'xial alignment of the ends of a tube, the combination of a sighting instrument positioned adjacent one end of the tube and having a principal optical axis, aligning means associated with said sighting instrument and adapted to inherently maintain said optical axis. substantially parallel to the axis of the said end of the tube adjacent the sighting instrument, ,a

target positioned adjacent the other end of the tube and provided with a plurality of angularly related target arms, said aligning means for the sighting instrument acting to permit the sighting instrument to be shifted around the tubein a circular path in order to bring the optical axis substantially into a plane containing the axis of said tube at the point of application of said sighting instrument and at least one portion of one 6. In a device 01- the class described for determining the co-axial alignment of the ends of a 7 tube, thecombination of a sighting instrument positioned adjacent one end of the tube and having a principal optical axis, aligning means associated with said sighting instrument and adapted to inherently maintain said optical axis substantially parallel to the axis of the said end of the tube adjacent the sighting instrument, a target positioned adjacent the other end of the tube and provided with an indicating scale, said aligning means for the sightingiinstrument acting to permit the sighting instrument to be' shifted around the 'tube in a circular path in orderto bring the optical axis substantially into a plane containing the axis of said tube at the point of application of said sighting instrument and at least one portion of said indicating scale.

'7. In a device of the class described for'determining the straightness of a vertical tube, the

combination of a sighting instrument positioned adjacent one end of the tube and having a principal optical axis, aligning means associated with said sighting instrument and adapted to in- 5 herently maintain said optical axis substantially parallel to the axis of the said end 01 the tube adjacent the sighting instrument, a target positioned adjacent the other end of the tube and provided with an indicating scale extending radially of the tube, said aligning means comprising a pair of spaced V elements adapted to contact the outer surface 0! the tube and acting to permit the sighting instrument to be shifted around the tube in a circular path in order to bring the optical axis in line with said indicating scale.

FRED E. PA'I'IDN. 

